#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <math.h>


#define mp make_pair
#define pb push_back
#define super_power_ON ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define pii pair<long long, long long>
#define all(a) a.begin(), a.end()
#define BigPair pair <pair <long long, long long>, pair <long long, long long>>
#define rt return
#define ll long long
#define X first
#define Y second

using namespace std;

ll gcd(ll a, ll b) {
	a = abs(a);
	b = abs(b);
	while (a != 0 && b != 0) {
		if (a < b) {
			swap(a, b);
		}
		a %= b;
	}
	if (a == 0) {
		return b;
	}
	else {
		return a;
	}
}


vector<pair<int, int>> p;
int n;
ll ans = 0;

int main() {
	super_power_ON;
	cin >> n;
	for (int i = 1; i <= n; i++) {
		int x, y;
		cin >> x >> y;
		p.push_back(make_pair(x, y));
	}

	for (int cur = 0; cur < n; cur++) {
		map<pair<int, int>, ll> kol_vo;
		for (int i = 0; i < n; i++) {
			if (i == cur) {
				continue;
			}
			pair<ll, ll> vec = make_pair(p[i].X - p[cur].X, p[i].Y - p[cur].Y);
			ll g = gcd(vec.X, vec.Y);
			vec = make_pair(vec.X / g, vec.Y / g);
			if (vec.first == 0) {
				vec = make_pair(0, abs(vec.Y));
			}
			if (vec.first < 0) {
				vec = make_pair(-vec.X, -vec.Y);
			}
			kol_vo[vec]++;
		}

		for (auto cur_ : kol_vo) {
			pair<ll, ll> vec = cur_.X;
			pii normal_v = make_pair(-vec.Y, vec.X);
			ll cnt = cur_.Y;
			if (normal_v.X == 0) {
				normal_v = make_pair(0, abs(normal_v.Y));
			}
			if (normal_v.X < 0) {
				normal_v = make_pair(-normal_v.X, -normal_v.Y);
			}
			if (kol_vo.find(normal_v) != kol_vo.end()) {
				ans += kol_vo[normal_v] * cnt;
			}
		}
	}
	cout << ans / 2;
}